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In PQ News
Call of the Month for July 2026 Through the EPRI Power Quality Knowledge (PQK) Hotline, a PQK member requested guidance regarding the recurring failure of high-wattage metal halide (MH) high-intensity discharge (HID) lamps in a university sporting facility. The facility has experienced a persistent pattern of lamp failures, averaging roughly 30 failed lamps per year over nearly a decade of operation and the PQK member solicited the Program 1 team’s help in trying to understand possible causes and approaches for further investigation. Fortunately, EPRI has extensive experience with lighting technologies and their field performance. Based on EPRI’s lighting experience the following discussion is intended to provide practical technical insight for PQ Hotline collaborators who may encounter similar questions. This PQ Hotline Call of the Month details a previous analysis that EPRI did that pertains to this PQ Hotline inquiry.
Most Popular PQ Documents (Based on Clicks)
- 04/19/2012 Hotline Call About Voltage Sags/Swells
- Management and Mitigation of Harmonics
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- PQ TechWatch Understanding and Preventing Harmonic Resonance
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EPRI Industrial PQ Training Videos
As a follow-up to our Industrial Power Quality training classes, we have posted these complementary training videos to help solidify the concepts for both utility members and their customers. The top three are listed here.
Visualizing PQ Drive Parameters for Improved Voltage Sag Ride-Through 
This video demonstrates the voltage sag susceptibility of AC drive systems and how to improve the drive’s robustness through parameter changes.
Understanding PLC Voltage Sag Ride-through: AC and DC Powered Systems
This video demonstrates the differences in voltage sag ride-through between an AC powered PLC system and a DC Powered PLC system.
Power Conditioning to Enhance Control System Voltage Sag Ride-Through: The Constant-Voltage Transformer
This video shows how a CVT can be utilized to harden the voltage sag response of an automated control system.